Polishing is being used more in the fabrication of semiconductor devices to achieve higher levels of integration. In polishing, two types of conditioning are typically used. In-situ conditioning conditions the polishing pad as wafers are being polished, and ex-situ conditioning conditions the polishing pads after the wafers have been removed from the pad.
Ex-situ conditioning has been used longer compared to in-situ conditioning but does have some drawbacks. Typically, ex-situ conditioning causes shorter pad life, a lower polishing rate, and worse polishing rate stability. On the other hand, in-situ conditioning has problems with across the die uniformity and particles, contamination, and micro-gouging. Therefore, a need exists for a polishing process in which conditioning of the pad is optimized to give a reproducible polishing process.